Launching Labour's pro-EU battle bus tour, Mr Johnson said the "extremist" tag was not incendiary but accurate, because those who wanted Britain to withdraw believed everything about Brussels was bad.

"It's an extreme view that there is absolutely nothing good about the EU at all.

"It's extreme - not to take the view that we ought to leave - but the view that you cannot find anything good to say about an institution that has done many good things, won the Nobel Peace Prize in 2012, is admired in terms of its role in keeping the peace on our continent, you can find nothing good to say about it whatsoever.

"It is like if I was to come in here and say we ought to leave Nato, and here's all the reasons, and Nato has done nothing good, I would be classified as an extremist.

"We can all find things that are wrong with the European Union, but they can't find anything that's right - and that suggests a kind of, a certain mentality, that is not rational, and not balanced."

Mr Duncan Smith hit back by accusing the Labour former cabinet member of engaging in "threats" and being "ridiculous".

Key points from Iain Duncan Smith's speech

EU has become 'a friend of the haves rather than have-nots'

Cameron failed to deliver a reformed EU

Britain is powerless to prevent further migration

Immigration putting pressure on housing, schools, NHS

Big corporates in Germany benefit, small firms in Britain lose out

Voting to leave will be shock the EU 'desperately' needs

Mr Duncan Smith said:

"I don't know in what world it is extreme to want to have your democracy back, power over what you do, control over your laws and the power to make decisions about your people, elected by British people and rejected by British people when you get it wrong.

"If someone wants to tell me that's an extreme position, then I want to know what defines that.

"It is not extreme to want democratic government in your country, to be responsible to the electorate and to make the laws that best help them rather than have 60% of those laws made in Brussels.

"Those people in Remain really need to stop throwing threats and ridiculous terms like that around. It just demeans them, and it demeans the debate."

Labour leader Jeremy Corbyn also used the launch to insist he was fully behind the Remain campaign despite his own "many criticisms" of the EU.

"I've made many, many criticisms of the European Union; I still make those criticisms," Mr Corbyn said as he insisted he backed the Remain stance in order to defend workers' rights and the environment.

"We see it as an act of solidarity with people who think like us across Europe; going it alone won't help them, and won't help us," Mr Corbyn said as he dismissed claims immigration was having a negative impact on wages and public services.

Brexit would make reducing immigration 'extremely difficult'

Delivering major reductions in immigration would be "extremely difficult" if Britain votes to leave the European Union, a prominent economist has said.

Jonathan Portes concluded that although the impacts of recent EU migration "appear to have been relatively benign" it "remains the most important issue for many, perhaps most" likely voters.

This means a vote to remain will "unequivocally" be a vote for the status quo in this area, he said.

Mr Portes, the former Cabinet Office chief economist, added: "A vote to Leave, however, will take us into new territory for UK immigration policy, with potentially significant consequences; as yet, we have almost no detail on what those might be."

If immigration and free movement are the determining factor in the referendum result, there may be strong political pressure on a post-Brexit government to deliver "very large reductions" in immigration to the UK, he wrote in a paper for the National Institute Economic Review.

"Both inside and outside the Government, those arguing for Brexit have long made the case that it is EU membership that prevents the Government from delivering its popular pledge to reduce immigration to 'the tens of thousands'," the article said.

Ministers have come under pressure over the objective after official figures repeatedly showed net migration at a much higher level.

The most recent figures showed estimated net migration - the difference between the number of people arriving and leaving - was 323,000 in the year ending September.

Mr Portes, a principal research fellow at the National Institute of Economic and Social Research, went on: "Without the 'excuse' of freedom of movement, the Government might be obliged to turn what is currently little more than an aspiration into a serious policy objective.

"In practice, this would be extremely difficult."

Separate analysis has claimed that applying the same migration rules to EU nationals as currently apply to non-EU citizens could reduce net migration by about 100,000.

Mr Portes said: "It follows that further significant reductions in non-EU migration - which is currently slightly higher than EU migration - would be required to meet the Government's pledge."

He said the economic consequences would be "significant".

Citing another study, the paper said a reduction in migration levels of 50% would require an increase in the tax rate on labour income of about 2% to preserve the budget balance.

It also warned that the consequences of restrictions for some industries that rely on migration from within the EU to fill low-skilled jobs "would be very large".

Alan Johnson defends Corbyn's holiday before EU referendum

Former home secretary Alan Johnson defends Jeremy Corbyn's decision to go on holiday at the end of the month as he launched Labour's six-week pro-EU battle bus campaign: "I'm the one sentenced to be on this coach, not Jeremy, and if he wants to take a few days' break when Parliament is in recess, great, he'll come back all the stronger."

Former home secretary Alan Johnson, Deputy Leader of the Labour Party, Tom Watson, Shadow Minister for Young People, Gloria De Piero, and Labour Party leader Jeremy Corbyn join activists as they launch the Labour In for Britain EU campaign battlebus on the South BankCredit:
PA

Iain Duncan Smith 'lying to his own people'

German MEP Elmar Brok, who was one of the "sherpas" during the renegotiation talks, said Mr Duncan Smith was "lying to his own people".

He told BBC Radio 4's World At One: "This, I think, is just not true.

Angela Merkel Credit:
Michaela Rehle

"Britain got what is possible under these circumstances and that was a great success story.

"It is not easy to sell in countries like Poland and others that Britain got this special right and therefore Duncan Smith is trying to explain to its people that Germany has a direct impact on British policy, that is just wrong. Mr Duncan Smith is lying to his own people."

Asked about The Sun's front page depicting German Chancellor Angela Merkel as a puppet-master controlling Mr Cameron, he replied: "This just a part of a dirty campaign and has nothing to do with reality."

'We should spend our money on our priorities'

Alan Johnson, the leader of the Labour In For Britain campaign, today branded people who support Brexit as ‘extremists’ and described the £350 million a week Britain sends to Brussels as a "drop in the ocean".

Gisela Stuart, chairman of Vote Leave, said: "The NHS is in crisis and it desperately needs more money. If we Vote Leave and take back control of the £350 million we give to the EU each week we will be able to give the NHS the shot in the arm it desperately needs. We should spend our money on our priorities.

Gisela Stuart, chairman of Vote LeaveCredit:
Claire Lim

"The remain campaign wants the elites to have more power and money, and not to give back control to the British people. Patients struggling to get care on the NHS will rightly think that they are completely out of touch when they claim that £350 million - enough to build a new hospital every week - is just a drop in the ocean."

IDS fighting for working people? 'Ludicrous!'

Iain Duncan Smith's claim to be fighting for working people has been labelled "ludicrous" by shadow minister Jonathan Ashworth.

"Working people will take Iain Duncan Smith's warnings about social injustice with a large pinch of salt," he said.

"After all, this is the Tory minister behind the bedroom tax and the man who opposed the introduction of the minimum wage and once warned that increased workers' rights through the European Union would lead to 'turmoil on the streets'.

Iain Duncan Smith with George Osborne in 2014Credit:
Getty Images

"The truth is Britain's EU membership protects workers, consumers and the environment. The risk is that if we leave the EU a Tory government would be free to launch an assault on rights at work secured by Labour and guaranteed under EU law."

TUC General Secretary Frances O'Grady said: "This is the man who cut tax credits, who cut disability benefits and who pushed half a million more children into absolute poverty.

"So we will take no lessons on social justice from the minister for foodbanks.

"He ignored the main Brexit problem everybody else is talking about: the big hit on jobs and wages that most economists predict.

"Working families have still not fully recovered from the economic crisis, so the last thing they need now is another hit on jobs and pay."

'Powerful German politicians deciding Britain's future'

Dominic Raab, the eurosceptic justice minister, has warned that the likes of Angela Merkel, the German Chancellor, are dictating Britain's future by forcing David Cameron to remove an emergency brake on migrants at the eleventh hour.

He told the BBC's World at One: "I think what the British people can see is that we've got powerful German politicians deciding such an important issue rather than the politicians who are accountable to them.

Dominic Raab, the eurosceptic justice ministerCredit:
EPA/WILL OLIVER

"We have all wanted to supported the PM for the very best terms. What it shows you how Angela Merkel has been in all of this and of course they are not accountable to the British people."

He also criticised Mr Cameron's suggestions that Britain quitting the EU could leave Europe open to future wars.

"I'm not going to engage in name-calling but we are not the ones scaremongering warning of world wars," he said.

No10: We made decision not to go for emergency brake on migrants

Downing Street said the decision not to push ahead with an emergency brake on migrants had been "made entirely" by the British government and endorsed by the Cabinet - which at that time included Mr Duncan Smith.

But No 10 failed to deny that discussions had taken place with Berlin about the emergency brake.

A spokesman said: "He didn't share the speech, he doesn't share speeches with foreign leaders and preventing migrant access to benefits for four years was a manifesto commitment.

"When the deal was agreed it had the full backing of Cabinet. It was a decision made entirely by the British government.

"The Prime Minister made clear at the time that the Government had looked at an emergency brake but he decided that was not the most effective way forward."

Alan Johnson, leader of the Labour In for Britain campaign, has claimed that those who are on the side of Brexit are "extremists".

Alan Johnson at the launch of the Labour In For Britain referendum campaignCredit:
PA/John Stillwell

"The people on the Brexit side can't give the EU any credit at all. We are the reasonable people, the Leave side, they are the extremists on this.

It's an extreme view that there is absolutely nothing good about the EU at all, not a single thing. They can't find anything good to say and I think that is extreme, That suggests a certain kind of mentality that is not rational and not balanced."

A summary of Iain Duncan Smith's key speech

Laura Hughes sends me this summary of the former Work and Pension Secretary's major speech this morning.

'A friend of the haves, not the have-nots'

Ian Duncan-Smith says the EU has become a "friend of the haves rather than the have-nots."

Wealthy Germany, banks and big corporates have all benefitted from their ties with Brussels, he says. But it's not working for the over regulated small businesses and lower-paid, lower- skilled Britons.

The former Work and Pensions Secretary talks about people from Eastern Europe hugely underbidding British workers for those work and says the Labour party's position on the EU is "ironic".

He says they are "acting against the interests of the communities they purport to serve. The downward pressure on wages is a trend will only get worse if we stay in the EU and we will continue to see house prices rise- young people are the biggest losers from this, he says.

He's now talking about the "compassionate instincts of the British people" and urging people who haven't done well from the EU.

This vote is happening at a role of "enormous global economic upheaval" which could see the "explosion of the have-nots", he says.

He says: "I have always wanted people to own their own home but that gets more difficult particularly for young people through our inability to control the scale of migration."

Pressure on schools and jobs

EU migration means extra school places have to be found, the equivalent to 27 secondary schools or 100 primary schools, he adds.

He makes the point that we are entering a period when white collar jobs are going to be replaced by technology and that in the increasing decades we will need to be able to compete with the populations of China and India.

"The EU is fast sliding into economic irrelevance", he says. "The EU can only move as quickly as its slowest member states and that means it can only move very slowly indeed. And in today's global economy is not speed that kills but indecision.

"EU leader and ministers spend so much time in Brussels, not agreeing decisions, that they aren't focuses on the challenge back in their home nations."

He insists the lesson of the Euro is that it's better to be in control of our own destiny, and that goes for other policy areas too.

'Let's vote for our own British independence day'

Iain Duncan Smith ends his speech with this call to voters:

Iain Duncan Smith delivers a Vote Leave speechCredit:
Tolga Akmen/LNP

"Given we are so uninfluential inside the EU, our maximum moment of influence might be in leaving. Confronting the rest of the EU with the need and opportunity to radically change its structures is the most socially just and, indeed, European-friendly service that Britain can provide to our neighbours across the Channel.

Surely like me you believe the UK can do better. Why should we set such a low vision about our future by tying it to this failing project.

Inside the EU our politicians can only talk of what we would like to do to change things knowing they will achieve very little. Outside the EU we can change our destiny and dare to believe in the greatness of all our citizens.

Britain deserves better than this which is why on 23rd June we should take back control and vote for our own British independence day."

£350m per week for EU could be spent on NHS

The NHS could benefit from the £350million per week heading to the EU, suggests Iain Duncan Smith

"We should be able to choose how we spend the £350 million that we currently send to Brussels every week. It would in any normal world be a strange choice to make for a British government that whilst bearing down on welfare spending and other budgets since the election we continue to send to this wealthy EU hundreds of millions of taxpayers money. This is money that could help fund the NHS. It could fund extra training and infrastructure to help every Briton to thrive in the coming economic age."

Immigration puts pressure on our schools

Immigration is having an impact on schools, warns Iain Duncan Smith

"As the Government's own recent figures show, to cope with the kind of pressure that immigration is placing on the schools system the taxpayer is having to find extra school places equivalent to building 27 new average-sized secondary schools or 100 new primary schools. So my Vote Leave and Conservative colleague Priti Patel was correct when she highlighted the fact that as always, when public services are under pressure, those without the resources to afford alternatives are most vulnerable. In short, getting a place in your local school gets more and more difficult."

Struggle for Briton's to own their own home will only get worse

Britons are struggling to get on the property ladder

"Another big negative economic effect of the level of immigration that the British people have never voted for - and do not want- is on house prices. Young people are the biggest losers from this. They are being forced to pay an ever larger share of their incomes on accommodation, are suffering longer commutes and often have to move far away from their families. We need to build around 240 houses every day for the next 20 years just to be able to cope with increased demand from future migration. Of course there are a number of issues in the difficulty to get housing in the UK but the impact of uncontrolled immigration make it a major factor in the demand for housing. Official data shows that over the last fifteen years, over two thirds (66%) of the additional households created in the UK were headed by a person born abroad.

The struggle to get on the housing ladder is one that affects families up and down the UK. Such is the pressure that the average age for a first time buyer is now 31.

Everyone should have the opportunity to own their own home, but as the EU continues to expand to other countries such as Macedonia, Albania, and Turkey, the population pressures that remaining in the EU would bring can only make that prospect less likely."

Migrants arriving in UK over next 10 years would fill a city size of Glasgow

Glasgow's Gallery of Modern ArtCredit:
Getty Images

"We know that EU migration has increased by 50% since 2010. If the number of EU jobseekers entering the UK over the next decade remains at current levels, some 690,000 people would be added to the UK population as a direct result. And with 5 more countries due to join, that number looks conservative. This would be the equivalent of a city the size of Glasgow."

How Olympic Park was constructed with cheap foreign labour

A view of the Olympic StadiumCredit:
PA

"The construction of the Olympic Park was a powerful illustration of the way in which immigrants undercut UK workers through their willingness to endure family-unfriendly living conditions. Visiting job centres in East London at the time I met both skilled and unskilled workers who struggled to get work on the site. When I asked why they said that people from Eastern Europe, often living in bedsits, without UK housing and family costs, hugely underbid them for their work. Since then those stories have been borne out by the facts. Despite the all the statements about the Olympic Park helping British workers, we now know that nearly half of all the jobs on the site went to foreign nationals."

EU works for Germany's big corporations at expense of small British families

"If the EU is working for Germany, for banks, for big corporates and for the public affairs companies with large lobbying operations in Brussels, the EU isn’t working for over regulated small businesses and lower-paid and lower-skilled Britons. They now have to compete with millions of people from abroad for jobs and a wage rise. The Government's own Migration Advisory Committee reported that for every 100 migrants employed twenty three UK born workers would have been displaced."

IDS pleads with well-off Britons to consider EU's impact on poor

Iain Duncan Smith begins his major speech by appealing to well-off Britons to consider the impact the EU has on those who were lower paid.

"My plea to better off Britons who have done well in recent years is to consider using their vote in the referendum to vote for a better deal for people who haven’t enjoyed the same benefits as them. Because the EU, despite its grand early intentions, has become a friend of the haves rather than the have-nots.

Take the euro, for example. It has greatly favoured already wealthy Germany and its export industries at the expense of southern Europe. The euro has meant serious unemployment for millions of young Greeks, Portuguese, Spaniards and Italians and has produced political extremism. The EU is also working well for big banks. The bailouts being financed by extreme levels of austerity in countries like Greece have largely benefited financial institutions that lent irresponsibly before the crash. The EU is also working for big corporates that benefit from mass immigration. Businesses that have under-invested for decades in the productivity and training of their own and local workforces have no reason to mend their ways so long as cheap labour can be imported from abroad."

Corbyn launches Labour's pro-EU battle bus

Jeremy Corbyn has given a speech in London to launch Labour's battle bus for the remain campaign.

Speaking in Waterloo the party leader said he is "overwhelmingly" in favour of staying in the 28 member-state bloc but warned he will continue to criticise the EU, particularly the Trans-Atlantic trade partnership (TTIP), a major tenant of the Brexit campaign.

He was joined at the event by Alan Johnson, the leader of Labour In, Gloria De Piero and Tom Watson.

Former home secretary Alan Johnson, Deputy Leader of the Labour Party, Tom Watson, Shadow Minister for Young People, Gloria De Piero, and Labour Party leader Jeremy Corbyn join activists as they launch the Labour In for Britain EU campaign battlebus on London's South BankCredit:
PA

Speaking in front of the red battlebus alongside a team of young Labour activists under big red umbrellas Mr Corbyn said: "Our campaign will be to remain but it will also be setting out a stall of what we want in the future."

He added that his campaign will focus on worker's rights, the environment and industry and said: "Going it alone won't help them [workers] and it won't help us."

Predicting a win for the Remain camp Mr Corbyn added: "I'm looking forward to this campaign and I believe it will be successful."

Asked if he agrees with Sadiq Khan that Labour must make a broader appeal to voters if it is to win the 2020 election Mr Corbyn said the party already has a big tent.

Deputy Leader of the Labour Party, Tom Watson, Shadow Minister for Young People and Voter Registration, Gloria De Piero, and Labour Party leader Jeremy Corbyn join activists as they launch the Labour In for Britain EU campaign battlebus on the South BankCredit:
PA/John Stillwell

In fact "it's enormous", he added, lamenting the fact that he was not currently stood under the tent and was instead getting soaked in the rain.

Mr Johnson said now that the local elections are out of the way Labour will focus all its attention on the campaign to keep Britain in the EU, claiming "every sinew will be stretched" to achieve the right result.

How Scotland could win EU referendum for David Cameron

The main pro-Europe campaign in Scotland has said Scottish votes could have a "potentially decisive impact" in the EU referendum.

Scotland Stronger in Europe said high levels of support north of the border for remaining part of the European Union could swing the vote nationwide on June 23.

The campaign held a briefing event at the University of Edinburgh as a Survation poll for the Daily Record put support for remaining in the EU at 76% among Scottish voters.

Scottish Conservative leader Ruth Davidson out and about campaigningCredit:
REX/Shutterstock

John Edward, senior campaign spokesman, said: "The referendum looks like being extremely close UK-wide, and we are putting all our supporters and activists on alert that the votes of the people of Scotland could make the difference in achieving a Remain result across the UK.

"The polls in Scotland suggest a very large potential Remain vote - stretching across the political spectrum and bridging both sides of the independence debate - and the turnout may also be higher in Scotland than south of the border.

"We are taking nothing for granted, the argument must be won in Scotland as elsewhere in the UK, but the potentially decisive impact of Scottish votes is one factor that we believe will mobilise people to back our positive campaign and vote Remain on 23 June."

The secretive art of striking deals in Europe

Iain Duncan Smith has a lot of people who followed the referendum scratching their heads this morning, writes Matthew Holehouse in Brussels.

But his comments on how Merkel torpedoed Cameron's bid for a proper brake on free movement are illuminating on how the business of striking deals in Europe is perceived in some quarters of the government.

Iain Duncan SmithCredit:
Telegraph / Paul Grover

A few observations:

We definitely knew this at the time. Merkel's intervention ahead of the speech in which Cameron asked for an emergency brake on benefits was well-publicised and indeed after Cameron dropped it she said how "pleased" she was. Not so subtle. Some accounts put the timing of her intervention much earlier than the IDS story would suggest, with her breaking the bad news in the British delegation room in Brussels in October 2014, more than a month before the benefits speech.

IDS complains that Merkel had a "de facto veto over everything." (Or in The Sun's parlance, a "secret veto".) Whisper it, but everyone did. The deal required unanimity of the 28 governments. Indeed in the closing hours of the renegotiation, Tsipras threatened to torpedo the lot as leverage over migration. And during the crucial December talks, Belgium, Greece and Portugal threatened to kick the entire migration package off the table.

Literally no-one liked this plan, because it was illegal, and a clear violation of the basic principle of free movement, which to many states is far more valuable than British membership. While there are some in Brussels who say Cameron could have asked for more, perhaps as much as a brake, the far broader consensus is that (like it or not) the package Cameron got scraped the envelope of the possible. Would Merkel have been doing Cameron a favour by promising to back a plan that would almost certainly have been shot dead by a combination of Juncker, Tusk, the 26 other leaders, the Parliament and the ECJ?

What this episode does underline is how, in the early days of the renegotiation, Cameron is said to have made himself remarkably reliant on Merkel in Europe, convinced that her support alone was the key to fixing his problems and deaf to the warnings of others. She, in turn, is said by allies to deeply resent the role of the all-powerful 'G1', and made clear Cameron would have to make his own allies if he wanted to find a deal. For a fantastic account of that "absurdly reliant" relationship, read Alex Barker's long piece.

Angela MerkelCredit:
Reuters

It's worth noting how badly much of southern and eastern Europe chafes at German dominance on the Euro and migration. Why would Merkel wish to add stripping eastern European workers in Britain of their benefits to that list of grievances?

(Indeed, she was a very quiet presence during the marathon talks that cemented the final deal in February. I'm not convinced that Merkel very publicly excusing herself to buy frites on Place Jourdan while Cameron haggled with Hollande and Belgium's Michel was an entirely incidental bit of symbolism.)

IDS spilling the secrets of Cabinet

David Cameron started his EU renegotiations by wanting to limit the number of people who can come to Britain and an emergency brake on migrants was considered to be one way to achieve that.

However, it was widely known that the Germans just weren't up for that and the proposal became an emergency brake on benefits instead.

Angela Merkel is thought to have been unhappy with the idea of an emergency brake on migrants coming to the UKCredit:
AP

Iain Duncan Smith has for the first time gone on record presenting this as a surrender to German control, offering a warts-and-all behind-the-scenes look at the secrets of the Cabinet which he later quit.

Interestingly No10 are not quite denying the claim, merely saying that the Prime Minister decided it was not the best way to proceed.

Cameron accused of allowing Germany to sabotage his EU deal

David Cameron has been accused by a pro-Brexit former cabinet colleague of allowing Germany to "veto" key parts of his EU reform renegotiation.

Iain Duncan Smith said Berlin exercised the "ultimate power" over what changes the Prime Minister sought from Brussels and was allowed to block the idea of a cap on foreign workers coming to the EU.

The ex-Tory leader, who quit as work and pensions secretary in March in protest at disability benefit cuts, accused Mr Cameron of being "compliant" as Conservative divisions on Europe continued to rage.

Iain Duncan SmithCredit:
Telegraph/Paul Grover

He will today follow Justice Secretary Michael Gove and former London mayor Boris Johnson in making high-profile speeches on the case for a "leave" vote in the referendum on June 23.

In an interview with The Sun, he said a key demand was ditched, at the behest of Berlin, from the draft of a key speech by Mr Cameron just hours before it was due to be delivered.

"It's like they were sitting in a room, even when they were not there. There was a spare chair for them - called the German chair. They have had a de facto veto over everything," he told the newspaper.

"I know that right up until the midnight hour, there was a strong line in there about restricting the flow of migrants from the European Union - an emergency brake on overall migration.

"That was dropped, literally the night before. And it was dropped because the Germans said if that is in the speech, we will have to attack it."

Iain Duncan Smith has set himself up for a spectacular clash with David Cameron todayCredit:
PA

He went on: "There is no question in my mind that keeping the Germans on side was the only thing that really mattered.

"We wanted to use the Germans to work the others in the room. They had the ultimate power over it."

The PM's failure to announce a cap or "emergency brake" on the overall numbers coming to the UK in the November 2014 speech setting out his demands - despite media reports he would do so - disappointed Eurosceptic Tory MPs,

Foreign Secretary Philip Hammond denied at the time that Mr Cameron "backed off" in the face of pressure from German chancellor Angela Merkel and said simply that the UK had "sought to work with our partners in the European Union".

In the eventual deal, the UK was granted to right to apply for a seven-year "emergency brake" under which new migrants will only receive the right to claim in-work benefits gradually over the course of four years.

"We put ourselves in a compliant position to another country which doesn't have your best interests necessarily at heart," Mr Duncan Smith said.

"We are now in a worse position than we were before. We have gone from wanting to lead in Europe to being on the end of a lead in Europe."